The building permit - AC - represents the document issued by the local public authority, based on which the applicant can carry out construction works. The building permit is issued by the Urban Planning Service within the Town Hall / sector where the land is located.

The authority issuing the building permit will establish a validity period of no more than 12 months from the date of issuance and it can be extended by another 12 months, during which the applicant is required to start the works. In this situation, the validity of the permit is extended for the entire duration of the works specified by the permit, in accordance with the technical project.
Failure to start or complete the works within the established deadlines leads to the loss of the permit's validity, requiring the issuance of a new building permit. If the characteristics do not change compared to the initial permit, a new building permit may be issued without the need for a new urban planning certificate.